Method of making ornamented rubber articles



L. H. L HOLLIER Filed April 24, 1954 METHOD 0F MAKING ORNAMENTVED RUBBER ARTICLES May 21, 1935.

i, gsf- LUL? 527' 5- Patented May 21, 1935y l y y 2,002,375

N UNITED;l STATES PATENT. yOFFICE: l a p waooazs C i ,A f A METHOD or MAKING ORNAMENTED y RUBBER AR'rroLns Leslie ILLHouier, Waltham, Mass., assignmto a Hood Rubber Company, Inc., VWatertown, i Mass., a. corporation of Delaware n ApplicationAprilvZl, 1934, Serial No. y722,122

Y Y 4 Claims. (Cl. 18-58) a n This invention relates to the manufacture of Figr2 is a cross-section of a dipping tank with ornamented rubber articles and especially to the a matrix form immersed ina dispersion therein production of rubber articles With both variein .accordance with the invention.

a gated -andcongured surfaces. This invention Fig. 3 is an elevation of the matrix form of A is an improvement upon the subject 'matter of Fig. 2 having ornamenting material deposited 5 the copending application of A. L. Diller and myupon it. self, Serial No. 713,167, Vfiled February 27, 1934, ,Fig. 4 is an enlarged section Vtaken along the 'for Method of making ornamented rubber are line 4-4 of Figi?.V f Y n ticles, and Vassigned to the same assignee asis Fig. 5 is a still greater enlargement, with parts the present application; Y broken away, ofthe form and ornamenting mal0 `In the procedure of that application a negaterial of Fig- 4 having a layer 0f backing rubber `tive form is provided having a configured surdeposited upon the same. face comprisingminiature valleys and hillsides, Fig. 6-is an elevation ofia lasted, ornamented `and upon this form is deposited an' ornamenting shoe constructed according to the invention.

l dispersion, preferably an aqueous dispersion of For the purpose of `deterring the effect of grav- 15:

`rubber including the" ldesired coloring agent, ity on the liquid dispersed ornamenting mate- 'which dispersionis permitted to settle ron the" ir, rial that is deposited upon the matrix form and regular surface ofthe' forrnunder the iniiuence for assisting it to dry in the disposition effected of surface tensionof the liquid and gravityftoV principally by surface tension,` the drying is acprovide ornamental effects. Aftersuch deposits celerated, which may be carried out by drying 5 procedure of the invention. i the surface of a reptile skin. The upper end of havefdried a backing layer of rubberfis molded in the presence of heat above ordinary room tem- Jupon" the ornamenting rubber againstthe form perature, preferably by heat from the body of fand isremoved with the` ornamenting deposits thematrix form itself. vadhered to its molded surface and with the,` sur- In order to fulll the object of providing defaee'rcoior 0f the backing rubber appearing beposits predominantly on all the hillsidesof the 25 Ytween the deposits! i f J V` final` article, the configured matrix form, upon 'Ii'hechiefflobjectsof the present invention are which the article is formed, is coated with a .to provide improved procedure whereby further dispersion ofthe ornamenting material which variations in the ornamental effects' may l'be is of such liquidity that by virtue of the meniscus obtained, and to` provide for convenience in the formed under the inuence'of surface tension the 30 procedure. dispersion will be disposed predominantly upon A further object is to obtain distinctive ornathe hillsides of the form surface, and provision mentation by encouraging the effect of surface is made for drying the dispersion, as above detension on a liquid dispersion of ornamenting scribed, with such rapidity that the dispersion material deposited upon the surface of a conretains such disposition and does not flow. un- 35 figured matrix form While deterring the effect der the effect of gravity to gather perdominantly of gravity on the deposited dispersion. on the lowermost hillsides as determined by the A more specific object is to provide for proposition of the form during the drying.v i ducing ornamenting deposits in such disposition After the drying operation a backing layer of 40 on the surface of the final configured article that rubber iS mOlded against the matrix form and 40 the deposits appear predominantly on all of the deposits and iS l'emOVed With the DOSVB impres- `miniature hillsides of the surface with the sur- Sion in its surface and the Ornamenting deposits face of the backing rubber appearing between disposed predominantly upon the miniature hillthe deposits, as distinguished from a disposition Sides 0f its Surface.

` of the deposits predominantly on only `certain The article, as in the case of the shoe chosen 45 of the hillsides, or predominantly on the tops for illustration, is then assembled with its other of the projecting surfaces, as disclosed in the parts upon a Shaping Support and VulaniZed.

last-mentioned application. Referring tothe drawing, the footwear form These and further objects will appear from may comprise an internal support l0 of generally the following description, reference being had to flat sides, upon which is mounted a layer of 50 the accompanying drawing, in which: matrix material, preferably rubber, presenting an Fig. 1 is an elevation, with parts broken away outer negative matrix surface Il having miniature and sectioned, of a chamber for heatingthe hills and valleys constituting a negative of the matrix forms in accordance with the preferred configuration, for example, a molded negative of the matrix sheath may be bound to the support and closed by a tape I2.

For the purpose above described the form may be heated along with others of its kind in a heating chamber I3 (Fig. l), as by a steam pipe I4. Good results have been obtained by heating the form toi approximately 150 F. l

The form is then taken from the heater and immersed in a tank i5 of dispersed ornamenting material, preferably an aqueous dispersion of rubber containing a suitable coloring agent, the dispersion preferably being of such liquidity that its solid matter comprises only about eight v"tov fifteen percent by weight of the dispersion. The proportion of solid matter is governed to some extent according to whether a deep or pale shade of the color is desired. In order to avoid objectionable trapping of air at the form surface, the

form may be preliminarly wetted, as by dipping it into a bath of Water before it is dipped into the ornamenting dispersion. v

While the form is yet heated it is removed from the tank I5 and is suspended as shown in Fig. 3 so that the superfluous dispersion Vwill drain from-it and the remaining dispersion will, by the action of surface tension, assume a meniscus-in which the coloring appears predominantly at all the hillsides of each valley as shownat I5, I6 in Figs. 3, 4 and 5. The heat from the form accelerates .the drying of the dispersion so that the meniscus does not sag materially to a disposition predominantly upon the lowermost hillside, but rather retains its more uniform disposition upon all of the hillsides of each valley.

A layer of rubber il (Figs. 5 and 6) isv then molded upon the form and deposits, preferably by depositing the rubber directly upon the form from an aqueous dispersion of the rubber. This layer is then removed with the deposits I6, I6 adhering to the hillsides of its surface and with its surface color appearing between the deposits. lIt is then mounted inside out and assembled with other footwear parts upon a shaping support I8 and vulcanized. f

Theiiat form i lis of such dimensions and proportions that the rubber is not objectionably stretched or wrinkled when it is shaped upon the foot-shaped support I8. The use of the iat form for the rubber-depositing steps of the procedure has the advantage that a number of the forms may be handled togetherv in a minimum space, and, also, the flat form makes for uniformity in the distribution of the ornamenting dispersion over its side surface, the draining being very nearly the same for all of the depressions.

I claim:

1. The method of making an ornamented rubber article which comprisesproviding a negative form configured with miniature valleys and hillsides in its surface, depositing on said form an ornamenting dispersion of such uidity that, after draining and at least partially drying, the residue -o-f the deposit appears in areas merging with areas of fainter hue, effecting such draining vand drying in the presence of heat, then depositing `upon the form a layer of rubber and removing the latter to provide a positive of the surface configuration with the ornamenting deposits adhered to its surface and with its surface color appearing between the areas of deepest hue of the deposits.

2. A method as deiined'in claim 1 in which the dispersion is of such fluidity and the heat is such as to so accelerate the drying that all of the hillsides of each valley receive the deepest hue of the deposit with lsubstantial uniformity.

3. VA method as defined in claim 1 in which the heat is supplied by heating the form before the ornamenting dispersion is deposited upon it and the draining and drying is effected while the form is still hot.

4. The method of making an ornamented rubber article which comprises providing a negative form configured with miniature Valleys and hillsides in its surface, depositing on said form an ornamenting dispersion of such fluidity that, ,afterdraining `and at least partially drying, the

residue of the deposit appears principally at the hillsides merging with areasv in the valleys of fainter hue, permitting the dispersion so to drain and effecting such acceleration of the drying that the Vmeniscus of the residue in each valley does not materially sag by gravity, then depositing upon the form a layer of rubber and removing the latter to provide a positive of the surface conguration with the ornamenting deposits adhered to its'surface and with its surface color appearing between the areas of deepest hue of the deposits.

LESLIE H. LI-IOLLIER. 

